The major objectives of our research program within the Institute of Dental Research during the last ten years has been to investigate the systemic and local effects of food components, nutrients and dietary patterns which affect growth, development and maintenance of oral tissues, as well as the susceptibility of teeth to dental caries. This research proposal focuses specifically on the effect of altered mineral metabolism (deficiencies, imbalances or excesses) on the development of the dentition and its caries susceptibility in experimental animals. The in vivo and in vitro organ culture studies proposed include both investigations with macro elements, such as calcium and phosphorus, as well as with micro or trace elements such as lithium, molybdenum, aluminum, strontium and others, including fluoride. The overall hypothesis which underlies these studies is that a number of trace elements when provided at optimal dosages during specific critical periods of the developing tooth affect either the organic matrix or the mineralization process conducted by ameloblasts and odontoblasts. These effects can be determined by dietary trace elements either independently or in association with fluoride. Identification of these specific time-dose relationships for selected minerals (i.e., lithium, strontium, aluminum) would enable the implementation of specific caries preventive programs based on trace element and fluoride administration.